The properties required generally for dyes for forming images includes (1) stability or fastness to heat and light and (2) molecular extinction coefficient and hue. Conventionally, as cyan dyes for forming images, indoaniline dyes that are obtained from phenol compounds or naphthol compounds and p-phenylenediamines are commonly used. However, these indoaniline dyes do not necessarily satisfy items (1) and (2) above, and therefore further improvement was desired. To improve item (1) above, the use of compounds described in JP-B ("JP-B" means examined Japanese patent publication) No. 60423/1987 or JP-A ("JP-A" means unexamined published Japanese patent application) No. 30759/1982 can be mentioned. However, although these dyes were indeed fast to heat and light, the hue was not good, and the dyes had undesired subsidiary absorption in the blue region. To improve item (2) above, the use of compounds described in JP-A No. 113077/1988 can be mentioned. However, these dyes were quite poor in fastness to light and heat.